Question

Determinati formula moleculara a substantei care contine 54,55% carbon,36,36% oxigen si 9,09%hidrogen,stiind ca 11 mg substanta ocupa in c.n. un volum de 5,6 ml.

Answer 1

C : 54,55%    : 12 = 4,5458   | : 2,2725 = 2
H : 9,09 %      : 1 = 9,09       | : 2,2725 = 4
O : 36,36%    : 16 = 2,2725   | : 2,2725 = 1   (C2H4O)n
n = m/M = V/Vm     M = mxVm/V = 44
(2·12 + 4·1 + 1·16)n = 44  ⇒ n = 1    C2H4O